rac1 proto-oncogene protein; Ras-related C3 botulinum toxin substrate 1; p21-Rac1; Ras-like protein TC25; cell migration-inducing gene 5 protein (RAC1)
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Function
- plasma membrane-associated small GTPase
- p21rac has relatively high intrinsic GTPase activity
- cycles between active GTP-bound & inactive GDP-bound states
- GTP-bound form binds to a variety of effector proteins to regulate cellular responses including:
- secretory processes
- phagocytosis of apoptotic cells
- epithelial cell polarization
- growth-factor induced formation of membrane ruffles
- isoform B has an accelerated GEF-independent GDP/GTP exchange & an impaired GTP hydrolysis, partiallt restored by GTPase-activating proteins
- regulated by:
- guanine nucleotide exchange factors (GEFs)
- GDP dissociation inhibitors
- interacts with the GEF proteins PREX1, RASGRF2, DOCK1, DOCK2 & DOCK7, which promote the exchange between GDP & GTP, & therefore activate it
- interacts with PARD6A, PARD6B & PARD6G (GTP-dependent)
- part of a quaternary complex containing PARD3, some PARD6 protein (PARD6A, PARD6B or PARD6G) & some atypical PKC protein (PRKCI or PRKCZ), which plays a central role in epithelial cell polarization
- found in a trimeric complex composed of DOCK1 & ELMO1, which plays a role in phagocytosis of apoptotic cells
- interacts with RALBP1 via its effector domain
- interacts with PLXNB1
- part of a complex with MAP2K3, MAP3K3, CCM2 & DEF6
- interacts with BAIAP2, BAIAP2L1, CYFIP1/SRA-1 & DEF6
- interacts with Y. pseudotuberculosis YPKA & PLCB2.
- interacts with NOXA1
- interacts with ARHGEF2
- interacts with NISCH (putative)
Structure
- the effector region mediates interaction with DEF6
- belongs to the small GTPase superfamily, Rho family
Compartment
- cell membrane; lipid-anchor; cytoplasmic side (putative)
- attachment to inner surface of plasma membrane requires prenylation of the C-terminal Cys (putative)
- melanosome, stage 1 to stage 4
Alternative splicing
named isoforms=2; Rac1A, Rac1B
Expression
- isoform B is predominantly identified in skin & epithelial tissues from the intestinal tract
Pathology
- expression of isoform B is elevated in colorectal tumors at various stages of neoplastic progression
More general terms
References
- ↑ UniProt http://www.uniprot.org/uniprot/P63000.html
- ↑ NIEHS-SNPs http://egp.gs.washington.edu/data/rac1/
- ↑ Kahn RA, Der CJ, Bokoch GM. The ras superfamily of GTP-binding proteins: guidelines on nomenclature. FASEB J. 1992 May;6(8):2512-3. PMID: https://www.ncbi.nlm.nih.gov/pubmed/1592203
- ↑ Segal AW, Abo A. The biochemical basis of the NADPH oxidase of phagocytes. Trends Biochem Sci. 1993 Feb;18(2):43-7. Review. PMID: https://www.ncbi.nlm.nih.gov/pubmed/8488557
- ↑ Manser E, Leung T, Salihuddin H, Zhao ZS, Lim L. A brain serine/threonine protein kinase activated by Cdc42 and Rac1. Nature. 1994 Jan 6;367(6458):40-6. PMID: https://www.ncbi.nlm.nih.gov/pubmed/8107774